These are the much-vaunted percebes, sea barnacles, pried at tremendous peril by specialized percebeiros who clamber down the wind-lashed cliffs to gather these morsels that sell for hundreds of euros in Madrid and other urban centers. It is very much worthwhile to view videos and read about these brave souls; every village memorializes those who have lost their lives in the pursuit of a delicacy too expensive for most locals but much in demand by tourists, like ourselves.